Rotary solenoid



H. PRATT Feb. 10, 1959 ROTARY SOLENOID Filed Sept. '7, 1957 INVENTOR Haraden Praff BY ,U 8M 41W ATTORNEYS 2,873,412 ROTARY SOLENOID Haraden Pratt, Springdale, Conn., assignor, by mesne assignments, to Bell & Gossett Company, Morton Grove,

., a corporation of Illinois Application September 7, 1956, Serial No. 608,475 4 Claims. (Cl. 317-192) is converted into angular motion which is utilized to perform useful work. Rotary solenoids of the general type under considerabroadly new. However, so far as I am aware, there has not heretofore been available a rotary solenoid or repair, and which would retain its original torque characteristics throughout its useful life. There are many examples of fields of utility where such require ments are essential. For example, such rotary solenoids may be used to actuate certain elements in electrically operated typewriters or teletypewriters which must operate at high speeds for prolonged periods of time and which are required to give reasonably trouble-free operation over a period of years.

One of the primary objects of the present invention is to provide a small and compact rotary solenoid which is capable of many millions of actuations during its useful life.

Another object of the invention is to provide a rotary solenoid which will retain its original torque characteristics throughout a long, useful life.

Another object of the invention is to provide a rotary solenoid which is reasonably silent in its operation.

Another object of the invention is to provide a rotary solenoid in which the problems of lubrication are reduced to a minimum and consequently in which the rate of wear on the solenoid is substantially reduced.

Still another object of the invention is to provide a rotary solenoid in which the extent of both longitudinal and angular movement of the movable member is accurately and definitely controlled.

Other objects and advantages of the invention will be pointed out in the following detailed description of an exemplary form of the invention. This detailed description has reference to the accompanying drawing wherein: Figure-1 is a longitudinal sectional view of a rotary solenoid assembly embodying the invention and taken generally along the line 11 of Figure 2;

Figure 2 is a transverse sectional view line 2- 2 of Figure 1; and

Figure 3 is an enlarged fragmentary sectional view taken along the line 3-3 of Figure 2. v

The rotary solenoid assembly is provided with a tubular housing 4 which is preferably of bronze or other nonmagnetic material. Magnet coils designated generally by the reference numerals 5 and 6 are positioned in longitudinally spaced relationship in the housing 4. The magnet coil 5 is provided with a cup-shaped casing 7 and a closure plate 8, both of magnetic material. The magnet coil 6 is provided with a similar cup-shaped casing 9 and a closure plate 10. A supporting bracket 11 may be attached to the assembly by any suitable means such as screws 12.

taken along the 2,873,412 Patented Feb. 10, 1959 6 are provided with windings 13 and 14, respectively, and these windings are preferably electrically connected in parallel to assure that the coils will be energized substantially simultaneously. The magnet coil 5 is provided with a core 15 of magnetic material and the coil 6 is provided with a similar core 16. Bronze sleeve bearings 17 and 18 are positioned in central aperturcs in the cores 15 and 16 respectively. The sleeve bearings 17 and 18 support a shaft 19 which extends centrally and longitudinally of the housing 4 and is capable of both longitudinal and angular movement relative to the cores l5 and 16.

An armature 20 is fixed to the shaft 19 adjacent the magnet coil 5 by any suitable means such as a set screw 21. The armature 20 may be provided with a peripheral flange 22 which may engage the surface of the closure plate 8 to limit longitudinal movement of the shaft 19 in the downward direction as seen in Figure l. Alternatively, the longitudinal movement of shaft 19 in this direction may be limited by engagement of the inner end 23 Magnet coils 5 and 15. An armature 25 is fixed to the shaft 19 adjacent the magnet coil 6 by means of a set screw 26. The armature 25 may be provided with a peripheral flange 27 which may have the same purpose as the flange 22. and 29 are received shaft 19. The lock as a set screw 3 The actuating plate 31 is provided rollers hereinafter described to impart angular motion to the shaft 19 upon longitudinal movement thereof. Three camming surfaces 33, 34 and 35 are illustrated as being spaced degrees apart around the periphery of the actuating plate 31. These camming surfaces are illustrated as being formed by striking portions of actuating plate 31 out of the plane thereof to form tongues which are clearly shown in Figures 2 and 3. After the carnming surfaces 33, 34 and 35 have been struck from the actuating plate 31, the plate may be suitably hardened and the camming surfaces may be accurately ground to the desired contour.

The camming surfaces 33, 34 and 35 are arranged to cooperate with rollers 36, 37 and 38, respectively. These rollers are pivotally mounted on fixed shafts or axes 39, 40 and 41, respectively, which extend radially with reference to the shaft 19. The shafts 39, 40 and 41 are fixed in U-shaped supports 42, 43 and 44 which are secured to the adjacent surface of the cup-shaped casing 9 of the magnet coil 6.

A crank arm 45 is fixed to the shaft 19 by means of a set screw 46 and extends radially from that shaft through an opening 47 in the tubular housing 4. A connecting rod the outer end of the crank spring member 50 has one of its ends attached to the outer end of the crank arm 45 and has its opposite end connected to any suitable fixed member, not shown. The outer end of the crank arm 45 is provided with a bumper portion 51 positioned to strike a cushioning member 52 which is preferably of rubber or some other suitable resilient cushioning material. Cushioning member 52 is supported by means of an adjustable bracket 53 which is secured to the tubular housing 4 by means of screws 54.

The operation of the apparatus can now be described. When the magnet coils 5 and 6 are not energized, the

spring-member ft urges the crank arm 45 in a clockwise direction as seen in Figure 2 and the elements of the apparatus occupy the positions shown in the drawing. Camming surfaces 33, 34- 311C135 are in engagement with the rollers 36,37 and'38, respectively, and the shaft 19 and all elements fixed thereto are thus in the'upwa rd position as illustrated in Figure 1. The lock nuts 28 and 29 serve to limit the extent of this upward movement. Energization of the magnet coils 5 and 6 causes the armatures 2t and and consequently the, shaft 19 and all elements fixed thereto to move in the downward direction as seen in Figure l. The actuating plate 31 will move downwardly with the shaft 19 and thereupon the camming surfaces 33, 34 and and the rollers 36, 37 and 38 will cooperate to cause counter-clockwise angular movement of the shaft 19 and the crank arm 45, as illustrated by the arrow 55 in Figure 2. The extent of this counter-clockwise movement of the shaft 19 and crank arm may be limited by engagement of the flange 22 of the armature 20 with the closure plate 4 8 of the magnet coil 5, or by engagement of the inner surface 23 of the armature 20 with the surface 24 of the core 15. The extent of such counter-clockwise movement could similarly be limited by engagement of corresponding portions of armature 25 with corresponding elements of the magnet coil 6. However, such means for limiting the counter-clockwise movement would not serve to definitely stop the crank arm 45 at any particular fixed position for the reason that the shaft 19 could continue to rotate after, for example, the flange 22 engaged the closure plate 8. For this reason it is preferable that the counterclockwise movement of the crank arm 45 be limited by engagement of the bumper portion 51 with the cushioning member 52. The position of the cushioning member 52 is adjustable by changing the position of the bracket 53 relative to the tubular housing 4. The bumper portion 51 will remain in engagement with the cushioning member 52 until the magnet coils 5 and 6 are tie-energized, at which time the spring member will return the assembly to the positions shown in the draw- The rollers 36, 37 and 33 are preferably of self-lubrh eating material to eliminate the need for other lubrication of those rollers and of the camming surfaces. The sleeve members 17 and 13 are preferably also of selflubricating material. The axial lengths of the rollers 36, 37 and 38 are sufficient to distribute the forces acting between those rollers and the camming surfaces 33, 34 and 35 to such an extent that excessive pressure is not exerted between those members. that the camming surfaces 33, 34 and 35 and the rollers 36, 37 and 38 perform no function in stopping or limiting the extent of movement of the movable portions of the apparatus and those members are therefore relieved from high stresses and shock which would otherwise exist. These features contribute greatly to the useful life of the camming surfaces and rollers and to the ability of the apparatus to retain its original torque characteristics.

The slope of the camming surfaces 33, 34 and 35 preferably changes gradually in the manner best illustrated in Figure 3 so that when magnet coils 5 and 6 are first energized the angular motion imparted to the shaft 19 and crank arm 45 is relatively slow but gradually accelerates as the shaft 19 continues to move downwardly under the influence of the magnet coils. This fact serves to reduce the stresses on the camming surfaces and the rollers and additionally serves to reduce the noise of the apparatus at the instant of energization of the magnet coils 5 and 6. The cushioning member 52 acts to reduce noise of the apparatus at the end of the working stroke of the crank arm 45.

I have illustrated and described what .I now consider to be the preferred form of theimventiom. 110mm,

it will be clear that modifications may be resorted to with- It will be observed out departing from the broadcrscope of the invention as defined by the following claims.

Having thus described my invention I claim:

1. A rotary solenoid comprising a casing, a magnet coil having a core fixed within said casing, a shaft extending through said core and being both longitudinally and angularly movable relative thereto, an armature fixed to said shaft, a flange on said armature positioned to engage said casing to positively limit longitudinal movement of said shaft in the power strokedirection of movement of said shaft, stop means fixed to said shaft and positioned to engage said casing to positively limit longitudinal movement of said shaft in the return stroke direction thereof, a plurality of rollers pivotally mounted at one end of said casing on fixed axes disposed radially relative to said shaft, an actuating plate fixed to said shaft, a plurality of portions of said actuating plate sloping therefrom to form camming surfaces positioned to engage said rollers, said carnming surfaces cooperating with said rollers to cause angular movement of said shaft in one angular direction upon longitudinal movement of the shaft in the direction of its power stroke, cushioning means limiting further angular movement of said shaft in said one angular direction at the end of the power stroke as determined by engagement of said flange with said casing, and spring means urging said shaft angularly in the opposite direction whereupon said rollers and camming surfaces move said shaft longitudinally for its return stroke upon de-energization of said coil.

2. A rotary solenoid comprising a casing, a magnet coil having a core fixed within said casing, a shaft extending through said core and being both longitudinally and angularly movable relative thereto, stop means fixed to said shaft to engage said casing to positively limit longitudinal movement of said shaft in both the direction of its power stroke and the direction of its return stroke,

a plurality of rollers pivotally mounted at one end of said casing on fixed axes disposed radially relative to said shaft, an actuating plate fixed to said shaft, a plurality of portions of said actuating plate in the form of tongues struck from the plane thereof sloping therefrom to form .camming surfaces positioned to engage said rollers, said camming surfaces cooperating with said rollers to cause angular movement of said shaft in one angular direction upon longitudinal movement of the shaft in the direction of its power stroke, cushioning means limiting further angular movement of said shaft in said one angular direction at the end of the power stroke thereof, and spring means urging said shaft angularly in the opposite direction whereupon said rollers and cammingsurfaces move said shaft longitudinally for its return stroke upon de-energization of said coil.

3. A rotary solenoid comprising a casing, a magnet coil having a core fixed within said casing, a shaft extending through said core and being both longitudinally and angularly movable relative thereto, an armature fixed to said shaft, a flange on said armature positioned to engage said casing to positively limit longitudinal move ment of said shaft in the power stroke direction of movement thereof, stop means fixed to said shaft and positioned to engage said casing to positively limit longitudinal movement of said shaft in the return stroke direction of movement thereof, a plurality of rollers pivotally mounted at one end of said casing on fixed axes disposed radially relative to said shaft, a flat actuating plate. fixed to said shaft, there being a plurality of portions of said actuating plate in the form of tonguesstruck from the plane thereof sloping therefrom to form camming surfaces positioned to engage said rollers, said cumming surfaces cooperating with said rollers to cause angular movement of said shaft in one angular direction uponlongitudinal movement of said shaft in the direction of its power stroke, said camrning surfaces merging smoothly and uninterruptedly and without abrupt changedn direct tion with the fiat surface of said plate whereby upon exs eessive angular movement of said shaft in said one direction said rollers may roll onto said flat surface of said plate, cushioning means limiting angular movement of said shaft in said one angular direction, and spring means urging said shaft angularly in the opposite direction whereby upon de-energization of said coil said rollers and said camming surfaces cooperate to move said shaft longitudinally in the direction of its return stroke.

4. A rotary solenoid comprising a casing, a magnet coil having a core fixed within said casing, a shaft extending through said core and being longitudinally and angularly movable relative to said core and casing, said shaft being movable longitudinally in the power stroke direction of movement thereof by energization of said coil, first stop means fixed to said shaft and positioned to engage said casing to limit longitudinal movement of said shaft in said power stroke direction, second stop means fixed to said shaft and positoned to engage said casing to limit longitudinal movement of said shaft in the return stroke direction of movement, a plurality of rollers pivotally mounted on said casing on fixed axes extending radially relative to said shaft, a flat actuating plate fixed to said shaft, portions of said actuating plate providing camming surfaces in the form of tongues sloping circumferentially and toward said rollers from the plane of said plate, resilient means urging said shaft in one angular direction to cause the slope of said tongues and said rollers to move said shaft longitudinally in said return stroke direction to the limit provided by said second stop means, movement of said shaft longitudinally in said power stroke direction by energization of said coil causing said camming surfaces and rollers to move said shaft in the opposite angular direction, and cushioning means to stop the angular movement of said shaft in said opposite angular direction after said first stop means stops the longitudinal movement of said shaft in said power stroke direction.

References Cited in the file of this patent UNITED STATES PATENTS Sansbury Sept. 14, 1948 2,539,090 Leland Jan. 23, 1951 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,873,412 February 10,[ 1959 Haraden Pratt It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as correc'tel below In the heading tb the drawings, containing Figures 1, 2', and 3, line 3, for "Filed Sept. 7, 1957" read M Filed Sept. 7,: 1956 e Signed and sealed this 16th dagyof June 1959.

(SEAL) I Attest: KARL :H. AXLINE ROBERT c. WATSON Attesting Officer Commissioner of Patents UNITED STATES PATENT OFFICE CERTIFICATE 6F CORRECTION Patent No. 2,873,412 February 10, 1959 Haraden Pratfi In the heading t6 the drawings, containing Figures. 1, 2', and 3, line 3', for "Filed Sept, '7, 1957" read Filed Sept, 7-,: 1956 Signed and sealed this 16th day; of June 1959.

(SEAL) Atfiest:

AXLINE ROBERT c. WATSON ,Attesting Offider Conmissioner of Patents 

